When these bones are put on a pyre ship and burnt (requires a tinderbox, hatchet and any type of non-pyre log), they will summon a Barbarian spirit, who may thank you for putting his soul to rest with an item. The reward may be a Dragon full helmet, various potions, runes or projectile ammunition. Many players will attempt killing mithril dragons in the hopes of obtaining a dragon full helmet drop; if unsuccessful, they can take any gained chewed bones to be burned in a pyre ship for another chance at gaining a dragon full helmet, however the chances of that are also rare. Note that using higher level logs does not increase chances of receiving a dragon full helm.

An Ancient Barbarian Spirit being laid to rest

Burning chewed bones via a pyre ship provides an experience bonus to burying any bones or spreading any demon ashes afterward. This bonus accumulates. Burning 2 chewed bones consecutively provides a bonus for burying twice as many bones as burning one chewed bone. Dying does not remove the accumulation of bonuses. Experience gained from the bonecrusher does not receive this bonus.